Ok I have used clen before. I remember the two weeks and two weeks approach. A buddy of mine said he did 4 days on 3 days off but idk about this method.
What I know from reading is clen is supposed to have an almost 3 day half life but I have seen this as low as 1.5 days. What I am getting at is there is some inconsistency in this department.
Clen is supposed to have an anti catabolic effect that wears off around 18 days to three weeks. It’s upregulated fat burning is also supposed to have a similar window. It should still burn fat after this time but it is at a lower level.
Some people use (double check this because I might be off) a beta2 up regulator to counteract this drop in fat burning. Basically if you can keep your receptors receptive to it then it will keep burning fat really well. One of the easiest up regulators to get a hold of is Benadryl. Again my facts might be off but it is some sort of up regulator for one of the beta receptors.

When I use clen I use it with my PCT to help keep my gains and burn the fat I get with bulking. I use the Benadryl and run it up to six weeks.

Out of your two plans, as long as you are just going for fat loss, then I think the two weeks on two weeks off is better.
With it’s long half life the only a few days off doesn’t seem like the receptors have long enough to clear and refresh.
If you want to put faith in the Benadryl then maybe two weeks on and only one week off as long as you are taking Benadryl the whole time.

There are some other up regulators out there so go read up and maybe another one is a better fit for you.

As far as going up in dose then down. I have 40mcg tablets I started with half for a few days then up to a whole one. After about ten days I went to 60mcg then 15 days I went to 80. I never went down I just stayed at that level until I stopped. What I do remember reading is not to go over 100mcg or maybe that was a friend who told me. I know I sweat easy at 40mcg.
Most tablets are dosed at 20mcg so I figure that is a standard dosage for a reason, but standard dosage is not for the side effect of fat burning.
Remember you are taking it for a side effect not it’s intended usage.